scholarly journals Mathematical Analysis of the Process Forces Effect on Collet Chuck Holders

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 492
Author(s):  
Enrique Soriano-Heras ◽  
Higinio Rubio ◽  
Alejandro Bustos ◽  
Cristina Castejon
Keyword(s):  
Mathematical Analysis ◽  
Wedge Angle ◽  
Bending Moment ◽  
Radial Force ◽  
Analytical Models ◽  
Torsional Moment ◽  
Process Forces ◽  
Clamping System ◽  
The Mathematical Model ◽  
Chip Removal

Chuck holders are widely used for jobs with high precision. A chuck holder consists of a nut with a tapered surface and a thin-slotted clamping sleeve typically made of hardened steel and named a collet. Chuck holders are, essentially, wedge mechanisms. In this paper, we investigated the reactions and strains due to the forces during the chip removal process in the contact elements or jaws of the collet by means of mathematical analysis. Deflections in the jaws of the collet arise with a high influence from the precision of the workpieces. The cutting or process forces cause an axial force, a radial force, a torsional moment, and a bending moment on the chuck collet, and, consequently, displacements and inclinations of the clamping system are caused. Therefore, the proposed analytical models are based on elasticity and contact theories. The mathematical model for determining the deflections of the clamping system force was developed and implemented using MATLAB. The results showed that the variation in the clamping force during rotation in a collet chuck holder mainly depends on the stiffness of the collet chuck holder and the stiffness of the workpiece. The results indicated that the collet should be vulcanized to minimize the deformations that affect the final product. The deflections of a collet chuck holder due to process forces depend strongly on the clearances, wedge angle, and stiffness of the collet.

The Influence of Loads Superposition, Deterioration Due to Cracks and Residual Stresses on the Strength of Tubular Junction

2017 ◽  
Vol 68 (6) ◽  
pp. 1267-1273
Author(s):  
Valeriu V. Jinescu ◽  
Angela Chelu ◽  
Gheorghe Zecheru ◽  
Alexandru Pupazescu ◽  
Teodor Sima ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Residual Stresses ◽  
Bending Moment ◽  
Combined Loading ◽  
Torsional Moment ◽  
Calculation Methods ◽  
State Of Stress ◽  
Cracked Structures ◽  
Total Participation ◽  
Theoretical Results

In the paper the interaction of several loads like pressure, axial force, bending moment and torsional moment are analyzed, taking into account the deterioration due to cracks and the influence of residual stresses. A nonlinear, power law, of structure material is considered. General relationships for total participation of specific energies introduced in the structure by the loads, as well as for the critical participation have been proposed. On these bases: - a new strength calculation methods was developed; � strength of tubular cracked structures and of cracked tubular junction subjected to combined loading and strength were analyzed. Relationships for critical state have been proposed, based on dimensionless variables. These theoretical results fit with experimental date reported in literature. On the other side stress concentration coefficients were defined. Our one experiments onto a model of a pipe with two opposite nozzles have been achieved. Near one of the nozzles is a crack on the run pipe. Trough the experiments the state of stress have been obtained near the tubular junction, near the tip of the crack and far from the stress concentration points. On this basis the stress concentration coefficients were calculated.

Research on Friction between Grade Flat Approach Slab and Sliding Material in Jointless Bridges

2019 ◽  
Author(s):  
Yufeng Tang ◽  
Bruno Briseghella ◽  
Junqing Xue ◽  
Peiquan Zhang ◽  
Fuyun Huang ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Life Cycle Cost ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Element Model ◽  
Expansion Joints ◽  
Approach Slab ◽  
Jointless Bridges ◽  
Friction Function ◽  
The Mathematical Model

<p>The application of jointless bridges has been increasing year by year, because it could reduce the life‐cycle cost and improve the riding comfort. The approach slab in jointless bridges does not only have the function of road transition which is the same as the approach slab in bridges with expansion joints, but also transfer and absorb the deformation produced by the thermal expansion and contraction of the girder. The Grade Flat Approach Slab (GFAS) horizontally placed on the subgrade is one of the most common types of the approach slab in jointless bridges. The material placed between GFAS and subgrade should be able to properly slide to reduce the stress in GFAS. The friction coefficient between GFAS and sliding material is an important parameter affecting the mechanical behavior of GFAS in jointless bridges. In this paper, the tests of GFAS with different sliding materials subjected to horizontal displacement were conducted to obtain the corresponding friction coefficients (from 0.34 to 0.68). The mathematical model of bilinear spring could be adapted to simulate the friction function between GFAS and different sliding materials. One Deck‐Extension Bridge (DEB) that is one type of jointless bridges was chosen as a case study. The finite element model was implemented by using Midas‐Civil software. The influence of GFAS with different sliding materials on the mechanical properties of DEB under temperature variation was investigated. It can be concluded that the influence of the friction coefficient between GFAS and sliding material on the bending moment of DEB should be taken into account.</p>

Moment Resisting Performance Analysis and Structure Optimization for Electric Actuator

2012 ◽  
Vol 522 ◽  
pp. 686-690
Author(s):  
Gui Cheng Wu ◽  
Yu Hui Liu ◽  
Deng Liang Yang ◽  
Jian Hui Deng
Keyword(s):  
Attitude Control ◽  
Pitch Angle ◽  
Structure Optimization ◽  
Bending Moment ◽  
Torsional Moment ◽  
Electric Actuator ◽  
Moment Resisting ◽  
Actuator System ◽  
Executive Mechanism ◽  
Large Moment

The development of altitude and remote control for aircraft requires larger rudder piece pitch angle, and Electric actuator needs to withstand larger bending moment as the attitude control executive mechanism. Traditional bending moment and torsional moment of Electric actuator rely on output shaft bearing which are difficult to meet the requirement of resisting large moment. Based on a particular type of Electric actuator system, this paper analyzes its moment resisting capacity, proposes an idea of seperating bearing objects of bending and torsional moment for aircraft, and designs an innovative actuator structure. Moment test experiments show that moment resisting capacity of the new Electric actuator is enhanced to 150% more than orginal one.

scholarly journals DESIGN OF UNDIRECT GUY WIRE TENSION METER BASED ON STRAIN GAUGE

2019 ◽  
Vol 13 (2) ◽  
pp. 111-120
Author(s):  
Agus Sasmito ◽  
Yudi Irawadi
Keyword(s):  
Tensile Stress ◽  
Design Process ◽  
Mathematical Analysis ◽  
Strain Gauge ◽  
Bending Moment ◽  
Load Cell ◽  
Wire Tension ◽  
Main Component ◽  
Design Result ◽  
Data Result

The safety of the tower is depend the tension of guy wire, where it must have the same tensile stress at all positions. To meet this requirement, the load cell guy wire is designed based on strain gauge. Load cell guy wire  is designed portable and it can detect stress of the guy wire indirectly. The main component of load cell is a beam, two hooks and a cylinder to form a bending moment force in the beam, the value of the bending moment on the beam will be directly proportional to the increase or decrease in force drag on guy wire. Design process of load cell doone using mathematical analysis, and then the load cell is calibrated by standard load cell, based on the data result of calibration is known that the stress at the guy wire load cell is close and under the yield stress of the load cell material, it is proved that load guy wire cell’s design result is safe to use.

scholarly journals SYNTHESIS OF PROGRAM AND FINITE LAWS OF MOTION IN ANALYTICAL MODELS OF CONTROL OF THE FINAL STATE OF BIOMECHANICAL SYSTEMS

2019 ◽  
Vol 19 (1) ◽  
pp. 93-99
Author(s):  
V Zagrevskiy ◽  
O Zagrevskiy
Keyword(s):  
Mathematical Model ◽  
Computer Program ◽  
Center Of Mass ◽  
Material Point ◽  
Object Motion ◽  
Reference Points ◽  
Analytical Models ◽  
Final State ◽  
Finite Control ◽  
The Mathematical Model

Aim. The article deals with developing a computer program to simulate the movement of the object with a given initial and final speed and fixed travel time. Materials and methods. The analysis, as a method of biomechanics, allows us to assess the biomechanical state of the athlete in real sports exercises. The function of motion synthesis is the ability to predict the trajectory and behavior of the biomechanical system at specified reference points of the phase structure of the simulated motion. The article deals with one of the methods of biomechanical synthesis of movements: synthesis of control of the final state of biomechanical systems, based on the reduction of finite control to a given program control after attenuation of the transient component of acceleration. The mathematical description of the object motion is based on the known law of finite control with feedback. Integration of the mathematical model constructed in the form of the differential equation of the second order was carried out by one of the numerical methods of integration: Runge–Kutta method of the fourth order of accuracy. Consideration of the method is based on a mathematical apparatus describing the motion of a material point, which can be represented by a common center of mass of a biomechanical system, a joint, a center of mass of a segment, etc. Results. The mathematical model of the motion of a material point with the given kinematic parameters of motion at the initial and final moments is implemented in a computer program in the Visual Basic 2010 language environment based on the integrated development environment Visual Studio Express 2013. The output provides numerical and visual support for simulation results. Conclusion. It is shown that the developed computer model of the method always implements the goal of motion: to transfer an object from a given initial state by speed to a given final state for a fixed time of movement.

Analytical and Numerical Prediction of Springback of SS/Al-Alloy Cladded Sheet in V-Bending

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Pankaj Kumar Sharma ◽  
Vijay Gautam ◽  
Atul Kumar Agrawal
Keyword(s):  
Analytical Model ◽  
Outer Layer ◽  
Numerical Models ◽  
Yield Criterion ◽  
Bending Moment ◽  
Analytical Models ◽  
Bend Angle ◽  
Radius Of Curvature ◽  
Al Alloy ◽  
First Case

Abstract The present work deals with the development of an analytical model incorporating the effects of anisotropy and strain hardening to predict the springback in V-bending of two-ply sheet metal using a punch profile radius of 15 mm and included a bend angle of 90 deg. In the analytical model, the total bending moment is determined from resulting bending stresses for two different layers arranged in parallel planes one above the other and a new radius of curvature after springback is determined by applying a negative bending moment. The two-ply sheet composed of layers of AA1050 and SS430 is characterized for its tensile properties to be used in analytical and numerical models for prediction of springback. To study the effect of each layer during bending operation, two possible cases of sheet placements during bending and springback are studied; i.e., in the first case, the inner layer is of AA1050 while the SS430 layer is the outer layer whereas in the second case it is opposite. In all the cases of springback experiments when the outer layer is of SS430, the springback values are higher than the values obtained with the specimens when the inner layer is of SS430. This could be attributed to the higher tensile strength of the stainless steel layer and the higher bending radius experienced by it. The springback behaviors are also analyzed by simulations using Hill's anisotropic yield criterion in abaqus software. The springback results obtained by simulations and analytical models are in good agreement in general; however, in some cases, discrepancy of more than 15% is observed in the analytical results when compared with the experimental results.

Analytical Computational Models for Relationship between Ultimate Bending Moment of Concrete Segments and Axial Force

2020 ◽  
Vol 853 ◽  
pp. 177-181
Author(s):  
Zhi Yun Wang ◽  
Shou Ju Li
Keyword(s):  
Numerical Simulation ◽  
Computational Model ◽  
Axial Force ◽  
Computational Models ◽  
Plane Deformation ◽  
Bending Moment ◽  
Analytical Models ◽  
Bending Moments ◽  
Axial Forces ◽  
Practical Engineering

Concrete segments are widely used to support soil and water loadings in shield-excavated tunnels. Concrete segments burden simultaneously to the loadings of bending moments and axial forces. Based on plane deformation assumption of material mechanics, in which plane section before bending remains plane after bending, ultimate bending moment model is proposed to compute ultimate bearing capacity of concrete segments. Ultimate bending moments of concrete segments computed by analytical models agree well with numerical simulation results by FEM. The accuracy of proposed analytical computational model for ultimate bending moment of concrete segments is numerically verified. The analytical computational model and numerical simulation for a practical engineering case indicate that the ultimate bending moment of concrete segments increases with increase of axial force on concrete segment in the case of large eccentricity compressive state.

scholarly journals Mathematical Analysis for the Optimization of a Design in a Facultative Pond: Indicator Organism and Organic Matter

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Facundo Cortés Martínez ◽  
Alejandro Treviño Cansino ◽  
María Aracelia Alcorta García ◽  
Vyacheslav Kalashnikov ◽  
Ramón Luévanos Rojas
Keyword(s):  
Organic Matter ◽  
Mathematical Analysis ◽  
Traditional Method ◽  
Hydraulic Retention Time ◽  
Fecal Coliforms ◽  
Indicator Organism ◽  
Land Area ◽  
Quality Requirements ◽  
Main Disadvantage ◽  
The Mathematical Model

Stabilization ponds are easy to operate and their maintenance is simple. Treatment is carried out naturally and they are recommended in developing countries. The main disadvantage of these systems is the large land area they occupy. The aim of this study was to perform an optimization in the design and cost of a facultative pond, considering a mathematical analysis of the traditional methodology to determine the model constraints (fecal coliforms and organic matter). Matlab optimization toolbox was used for nonlinear programming. A facultative pond with the traditional method was designed and then the optimization system was applied. Both analyses meet the treated water quality requirements for the discharge to the receiving bodies. The results show a reduction of hydraulic retention time by 4.82 days, and a decrease in the area of 17.9 percent over the traditional method. A sensitivity analysis of the mathematical model is included. It is recommended to realize a full-scale study in order to verify the results of the optimization.

scholarly journals Silo with a Corrugated Sheet Wall

2013 ◽  
Vol 21 (3) ◽  
pp. 19-30 ◽  
Author(s):  
Csaba Németh ◽  
Ján Brodniansky
Keyword(s):  
Computational Models ◽  
Bending Moment ◽  
Physical Models ◽  
Experimental Measurements ◽  
Bending Moments ◽  
Bulk Materials ◽  
Production And Consumption ◽  
Thin Walled ◽  
The Mathematical Model

Abstract Silos and tanks are currently being used to create reserves of stored materials. Their importance is based on balancing the production and consumption of bulk materials to establish an adequate reserve throughout the year. The case study introduced within the framework of this paper focuses on thin-walled silos made of corrugated sheets and on an approach for designing these types of structures. The storage of bulk materials causes compression or tensile stresses in the walls of a silo structure. The effect of a frictional force in the silo walls creates an additional bending moment in a wave, which ultimately affects the resulting bending moments. Several mathematical and physical models were used in order to examine various types of loading and their effects on a structure. Subsequently, the accuracy of the computational models was verified by experimental measurements on a grain silo in Bojničky, Slovakia. A comparison of the experimental and mathematical models shows a reasonable match and confirms the load specifications, while indicating that the mathematical model was correct.

Calculation of Horizontal Sectional Loads and Torsional Moment

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Vladimir Shigunov ◽  
Alexander von Graefe ◽  
Ould el Moctar
Keyword(s):  
Free Surface ◽  
Shear Force ◽  
Three Dimensional ◽  
Bending Moment ◽  
Green Functions ◽  
Container Ship ◽  
Horizontal Shear ◽  
Torsional Moment ◽  
Oblique Waves ◽  
Rankine Source

Horizontal sectional loads (horizontal shear force and horizontal bending moment) and torsional moment are more difficult to predict with potential flow methods than vertical loads, especially in stern-quartering waves. Accurate computation of torsional moment is especially important for large modern container ships. The three-dimensional (3D) seakeeping code GL Rankine has been applied previously to the computation of vertical loads in head, following and oblique waves; this paper addresses horizontal loads and torsional moment in oblique waves at various forward speeds for a modern container ship. The results obtained with the Rankine source-patch method are compared with the computations using zero-speed free-surface Green functions and with model experiments.

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